Celebratio Mathematica

incollection S. S. Chern: “Fam­il­ies of hy­per­sur­faces un­der con­tact trans­form­a­tions in ${\mathbb{R}}^n$,” pp. 49–​56 in In­ter­na­tion­al sym­posi­um on num­ber the­ory and ana­lys­is in memory of Hua Loo Keng (Beijing, 1–7 Au­gust 1988), vol. II: Ana­lys­is. Edi­ted by S. Gong, Q.-k. Lu, Y. Wang, and L. Yang. Series in pure and ap­plied math­em­at­ics 21. Spring­er (Ber­lin), 1991. MR 1135825 Zbl 0819.​53009